Shoe upper assembly



April 7, 1970 J. G.S1"EADMAN ET AL 3,504,450

SHOE UPPER ASSEMBLY Original Filed Nov. 15, 1963 3 Sheets-Sheet 1 FIG.1.

April 7, 1970 J. c. STEADMAN ET AL 3,504,450

SHOE UPPER ASSEMBLY Original Filed Nov. 15, 1963 3 Sheets-Sheet 2 April7, 1970 J. G. STEADMAN ET AL 3,504,450

SHOE UPPER ASSEMBLY Original Filed Nov. 15, 1963 3 Sheets-Sheet 5 UnitedStates Iatent G 3,504,450 SHOE UPPER ASSEMBLY John German Steadman,Bristol, and Raymond Charles White, Hanham, Bristol, England, assignorsto Soundwell Investments Limited, Morely Road, Soundwell, Bristol,Gloncestershire, England Original application Nov. 15, 1963, Ser. No.323,972, now Patent No. 3,397,418. Divided and this application May 23,1968, Ser. No. 731,423

Claims priority, application Great Britain, Nov. 18, 1962,

35,575/62; Oct. 23, 1963, 41,918/63 Int. Cl. A43b 23/00 US. Cl. 3646.5 1Claim ABSTRACT OF THE DISCLOSURE A shoe upper assembly ready for lastinghaving an outer layer, a separate inner layer and stiffener elementslocated between the layers. The connection between the layers and thestiffener elements is by adhesives in the absence of stitching.

This application is a division of our earlier application, Ser. No.323,972 filed Nov. 15, 1963, now Patent No. 3,397,418.

This invention relates to a shoe upper assembly.

In the production of known shoe upper assemblies a lining, which may beof fabric or leather, is attached to the outside material by the use ofadhesive cement, or by using a fabric coated with a film which can besoftened by heat, the lining being ironed on to the outside material andsuch ironing constituting a first operation. A toe puff is also cementedto the upper by another operation. The top edge of the upper is thenbound by a fabric binding, or the outer material is turned over at thetop edge, and the edge of the binding or the turned over edge is thencovered by a piece of material either stuck or stitched to the assembly,constituting a third operation.

It is an object of the invention to provide an improved shoe upperassembly, the production of which requires fewer operations and is moreexpeditious than heretofore.

A further object is to provide a shoe upper assembly having an outsidelayer and an inside layer bonded together, the upper layer beingsubstantially complete so that an entire shoe, except for the bottom,can be formed therefrom. The upper layer is fiat and has two edgescontoured so that when held together they form a three dimensionalshape. This product thus permits a reduction in the level of skill, theequipment and the amount of work to form the upper assembly, therebysaving cost, time, space and equipment.

Another object of the invention is the provision of apparatus wherebyunskilled labour may be employed in a method hitherto requiring a highdegree of skill.

Similarly, common side seams, as well as the joining of differentlycoloured leather in some designs, have always involved machinestitching, which was time consuming and which required skill andequipment. Now such joints can be produced without skill, without anyspecial equipment, and without any additional time element, beyond thatinvolved in the initial assembly, assisted by the locating pins of theinvention, so there is a great economy in production.

Furthermore, the seams so produced are neater than those made bystitching, are impervious to water, and are stronger, as there are noneedle perforations and no thread which weakens with use.

According to the invention, a method of bonding simultaneously anassembly of the components of a shoe ice upper comprises uniting thecomponents under pressure by the activation of an adhesive byelectromagnetic oscillations. Such oscillations may be high frequencyoscillations, providing dielectric heating, effected by placng theassembly in a high frequency field so that heat is generated within theassembly through dielectric losses. Alternatively, activation of theadhesive may be accomplished by microwave heating, by the use ofelectromagnetic oscillations having -a frequency in the range ofapproximately 3000 to 30,000 megacycles per second. The betterutilization of energy at these frequencies allows for the use of smallergenerators to produce comparable effects, so that there is aconsiderable saving in initial cost over high-frequency heating.

At least the major part of the pressure may be applied as a separatestep immediately after the step of activating the adhesive. The pressuremay be effected between cooled elements.

The use of assembling jigs is very common in certain industries, but inthe shoe industry, it is revolutonary. The use of such devices has neverbeen regarded as practical in this industry, owing to the irregularshapes of the components and to their relatively flimsy nature. Theparts of the assembly may, however, according to the present invention,be assembled and secured together temporarily in a jig, then passed byconveying means to a heating enclosure, and thence to elements for theapplication of pressure. The conveying means may comprise an endlessbelt of glass fibre fabric impregnated with P.T.F.E.

The parts of the assembly may be secured together temporarily by spacedspots of a pressure sensitive adhesive, or by localized spot bonding byheat and pressure.

The heating enclosure may comprise a box served by a waveguide, wherebyelectromagnetic oscillations in the range of approximately 3000 to30,000 megacycles per second are conducted into the box to form astanding wave, opposite sides of the box being apertured to permit theconveying means to pass therethrough.

In the method according to the invention there may be employed aseparated stiffener, in which event the assembly may be united betweenthe flat platens of a press. Alternatively, the method of bonding mayemploy a one-piece stiffener of the usual shape, as will be describedhereinafter.

In either event, components of the assembly may conveniently be formedbefore union with holes to register with pins to locate them during theapplication of the pressure.

Surface decoration such as stitch marking, design embossing, orperforating, of the outer surface of the outside material may beeffected during the bonding.

The platens may be formed as curved beds, and the forepart and sides ofthe assembly may be shaped during the bonding. The outside material maybe made up of two or more pieces of dissimilar substances, for exampleleather and nylon, possibly of contrasting colours. Such substances maybe united during the bonding.

The invention will be described with reference to the accompanyingdrawings, in which:

FIGURE 1 is a diagrammatic perspective view of a flat bed press,indicating the parts of an assembly,

FIGURE 2 is a view of the outer surface of an assembly after bonding,

FIGURE 3 is a view of the inner surface of the assembly,

FIGURE 4 is a diagrammatic fragmentary plan of a microwave heatinginstallation, and

FIGURE 5 is a diagrammatic perspective view of the enclosure thereof.

Referring to FIGURES l to 3 of the drawings, in one embodiment of theinvention, employing a separated stiffener enabling the assembly to beunited in the fiat, a press has a flat lower platen 10, of the usualconstruction, and a fiat upper platen 11 faced with a relatively thickpad 12 of rubber or other suitable material to form a blanket. Theplatens 10, 11 constitute the high frequency electrodes. The lowerplaten is provided with a number of spring-loaded locating pins 13 whichare normally urged upwardly to project above the operative surface ofthe platen 10 but are enabled under pressure to retreat to a positionlevel with the assembly. The pins 13 are suitably arranged, both asregards number and location, to enable the parts of the assembly to behe d against unwanted displacement, and for this purpose such parts ofthe assembly as require such location are preformed with holes such as14 arranged to receive the locating pins 13 and so retain the parts onthe lower platen 10.

The top edge 15 of the outer material 16 is bound or turned in (seeFIGURE 3) and said outer material 16 is then located on the lower platen10, with its outer surface 16a lowermost, and a toe puff 17 and thehalves 18, 19 of a separated stiffener are located on the outer material16, each of said components being retained by one or two locating pinsand a suitable adhesive being provided over either or both of any twomating surfaces. The lining 20 is then laid over the assembly so farformed, suitable adhesive again being present. The upper platen 11 isthen brought down on to the components and pressure is applied. Asuitable pressure is of the order of 80 lbs. per square inch. Theassembly is then subjected to the effect of a high frequency field, thepower and time cycle being appropriate to suit the materials being used,and the components of the assembly are thus bonded together byactivation of the adhesive so that the faces which lie against oneanother and are coated with the adhesive are caused to adhere.

It will be appreciated that during the application of the HF. energy,heat is generated mainly in those com ponents of the assembly which havehigh dielectric losses. Thus the adhesive will attain a hightemperature, and so will components made of, for example, P.V.C., butleather will not become vely hot, and so will not suffer any damage.

The heat to which the leather or other material is subjected during theprocess has a beneficial effect on the lasting or shaping properties,the finished shoe keeping its shape better and presenting a moreattractive appearance due to this, as well as to the neatness of allvisible seams or joints.

Plasticised polyvinyl acetate, with or without the addition of modifyingagents, is suitable as an adhesive for this process. Other adhesives maybe based on acrylic esters, with or without additional crosslinkingresins, such as melamine formaldehyde condensation products,polyurethanes, again with or without cross-linking additives, otherthermoplastic materials, such as polyvinylidene chloride, or-elastomers,such as polychloroprene.

The outer material may be made of dissimilar or contrasting substances,such as nylon and leather.

In another embodiment of the invention, where a onepiece mouldedstiffener is to be employed, and a curved bed is used, steps will haveto be taken to prevent the lining from bonding to the upper material,whilst these are in the press, either by omitting the thermo-softeningcement from the area which will form a pocket for the stiffener, or byseparating the two components over the area in question with, forexample, a sheet of paper, which may be treated so as to prevent thecement from adhering thereto.

When a curved bed is used, this will normally be placed on the bottomplaten of the press, and will form the bottom HF. electrode. It will,therefore, be made of a conductive material, or will incorporate asuitably positioned conductive layer. An extra thick resilient pad willbe used as the top pressure element. This pad, which may be made ofcellular rubber or rubber-like material, will have incorporated withinits thickness, and relatively near to its bottom surface, a deformableelectrically conductive layer, which may be formed of a thin wire mesh,and which will form the top I-LF. electrode.

The bonded assembly will normally be removed from the HF. press whilststill hot. The adhesive will, therefore, be soft, and the assembly willbe somewhat vulnerable until it cools down and the adhesive hardens.This can be avoided by modifying the process so that the H.F. energy isapplied to the assembly without, or with only a slight pressure, thefinal pressing, or consolidating sage, being carried out immediatelyafterwards between cooled platens or curved elements, the assemblyleaving this stage as a strongly bonded unit, capable of withstandingany mechanical strain that the next manufacturing stage may impose uponit.

Referring to FIGURES 4 and 5, a different technique can be employed,using the microwave heating sys em, in which energy in the form ofelectromagnetic oscillations having a frequency in the range ofapproximately 300030,000 megacycles per second is conducted throughsuitably designed wave guides 21 into an oblong enclosure 22, soproportioned that a standing wave is Produced within it, along itslength. The enclosure 22 is an oblong rectangular metal box, positionedhorizontally, with the wave guide 21 connected to it at one end, andformed with two horizontal slits 23, one in each of its vertical sides24, so that the assembly can easily be passed through it by an endlessband 25, which may be made of a glass fibre fabric, impregnated withP.T.F.E. At this stage the assembly will preferably have been removedfrom its assembling jig, the various components being secured togetherin a temporary manner, for example by small spots of a pressuresensitive adhesive, or by spot welding. Immediately after passingthrough the enclosure, the assembly will be consolidated by pressure, ashereinbefore described.

The heating will be most intense in the areas around the nodal points ofthe standing wave. This effect can be neutralised by passing the endlessband 25 with the assembly through the enclosure 22 not at right anglesto its longitudinal axis, but at an angle of about 3045, as shown inFIGURE 4, when a uniform heating will be obtained.

This method of heating is more efficient than that produced by the useof lower frequencies, which means that higher production speeds, withlower installation costs, are possible.

Although a press will usually be employed for the purpose ofconsolidating the heated assembly, it is possible to do this by means oftwo pressure rollers 26, 27, at least one of which has a resilientcovering.

We claim:

1. A shoe upper assembly having an outer layer and a separate innerlayer bonded together, and stiffener elements located between saidlayers, the connection between said layers, including the connection ofthe layers to the stitfeners, being complete over the area of the innerlayer, by adhesives in the absence of stitching, said upper beingsubstantially complete so that an entire shoe, except for the bottom,can be formed therefrom, said upper assembly being substantially flatand having two edges curved such that when they are attached togetherthe said substantially flat shoe upper will be held in athree-dimensional shape to form a complete upper ready for lasting.

References Cited UNITED STATES PATENTS 1,836,926 12/1931 Levotch 36472,622,052 12/1952 Chandler 3645 2,955,366 10/1960 Zuckcrman 3646,5

PATRICK D. LAW$ON, Primary Examiner

